Some measurement tasks, such as four-terminal (Kelvin) resistance measurements and the measurement of the threshold voltage of multiple FETs, require that feedback loops be established between more than one source circuit and more than one sense circuit. Currently-available measurement equipment, such as the model 4142B modular DC source/monitor formerly sold by Agilent Technologies, Inc., Santa Clara, Calif., can only establish a feedback loop between a single source circuit and sense circuit, and is therefore unsuitable for performing measurement tasks that require multiple feedback loops.
Accordingly, what is needed is a measurement apparatus in which respective feedback loops can be established within multiple pairs of sense circuits and source circuits.